Since it is anti reflecting coating, it should not reflect..ie it must satisfy condition for destructive interference which is 2utcosr=n lambda. what's wrong? t

Q42. An anti-reflection film coating of thickness 0.1 um is to be deposited on a glass plate for normal incidence of light of wavelength 0.5 um. What should be the refractive index of he film? (Specify your answer to two digits after the decimal point) Ans.: 1.25 Solution The condition for constructive interference is 24ut=m+|, where m=0,1,2 .1or m =0 2/2 0.5x10 m =125 28/37 u= 2 4 4x0.1x10 m